OS: Ubuntu 11.04 x64Arduino IDE: 1.0 (x64)Arduino device: Arduino UNO R3Problem:I was using arduino uno for a project which has to do with PollSerial communication. I have also attached on it the Video Experimenter Shield (http://nootropicdesign.com/ve/).When I am trying to upload a new sketch I always detach the VE from arduino.2 weeks ago, I could not upload a sketch anymore to the arduino. The result message from the arduino was: Error opening serial port '/dev/ttyACM0'. Then while searching on google, I decided to buy one more Arduino UNO R3 device. When I first tried to upload a sketch the result is the same. "Error opening serial port '/dev/ttyACM0'."The error from IDE is this: